Methods of measuring shapes or the like measurement targets (measurement objects) using light have excellent characteristics of non-contact and non-destruction, and thus applications of the methods to industry and medical fields and fields of basic sciences are expected. As shape measurement devices using light, for example, various methods such as a method called a so-called moiré method of using a coded pattern of light and a method based on a ranging technique have been proposed.
For example, Patent Document 1 discloses a 3-dimensional measurement device that includes chirped optical pulse generation means for generating a chirped optical pulse of which a color is regularly changed over time and 3-dimensional information acquisition means for acquiring the chirped light from the chirped light generation means via a measurement object and forming 2-dimensional information of reflected light at a measurement standard time at which the chirped light is acquired into 3-dimensional information based on light color. In the 3-dimensional measurement device, acquisition light can be obtained via a measurement object when the measurement object is irradiated with the chirped optical pulse generated by the chirped light generation means. The color information of the acquisition light acquired by the 3-dimensional information acquisition means at the measurement standard time is related to a 3-dimensional shape of the measurement object.
As another shape measurement technology, for example, Patent Document 2 discloses a 3-dimensional shape measurement method (a shape measurement method) of measuring a distance to a measurement target using a time from emission of light to the measurement target to detection of a reflected image and coding a sequence of the emitted light and performing distance measurement by decoding the reflected image of the coded light. In the 3-dimensional shape measurement method, planar light or substantially planar light is used as light emitted to the measurement target. The sequence of the light is coded by changing the wavelength of the emitted light or an emission timing of the light.